Effect of strontium and melt purification on the solidification microstructure of hypereutectic Al-Si alloys. (March 2023)

• Record Type: Journal Article
• Authors: Chen, Wenyao; Liu, Ya; Peng, Haoping; Wang, Jianhua; Su, Xuping
• Is Part Of: Materials today communications. Volume 34(2023)
• Publication Date: 2023-03
• Subjects: Hypereutectic Al-Si alloy -- Strontium element -- Melt purification -- Synergy -- Solidification structure; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2022.105310
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: The combined effect of Sr and melt purification on the solidification structure of hypereutectic Al-Si alloys was studied by optical microscopy, scanning electron microscopy, X-ray diffractometry, and differential scanning calorimetry. The results showed that different strontium contents have a certain inhibitory effect on the precipitation of primary silicon in Al-20Si alloy. A strontium content of 0.3 wt% completely inhibited the precipitation of primary silicon in Al-16Si alloy. The synergistic effect of melt purification and 0.3 wt% Sr eliminated primary silicon from the solidified structure of Al-Si alloy with a silicon content of less than 20 wt%. It also transformed the solidified structure of Al-20Si alloy into pseudo-eutectic. Therefore, the synergistic effect of an appropriate amount of Sr and melt purification suppressed the precipitation of primary silicon in hypereutectic Al-Si alloys. Graphical Abstract: ga1 Highlights: 0.3 wt% Sr can inhibit precipitation of primary Si in hypereutectic Al-Si alloys. 0.3 wt% Sr can eliminate the primary silicon in Al-16Si alloy. If Sr is more than 0.3 wt%, Al2 Si2 Sr forms in hypereutectic Al-Si alloy. Microstructure of melt purified Al-20Si alloy with 0.3 wt% Sr is pseudo-eutectic.